Rukia could be a great character to pair with Ichigo in a different world crossover. She has her own set of powers and a calm, intelligent mind. In a strange new world, she could help Ichigo analyze new situations and come up with strategies. Their bond as comrades from the Soul Society would be interesting to explore in a different setting.
Orihime is another character that would work well with Ichigo. Her healing abilities could be crucial in a dangerous different world. Also, her kind - hearted and sometimes naive nature could provide some light - hearted moments and a different perspective in the face of the unknown. Ichigo would have to protect her while also relying on her support, which could strengthen their relationship in a new context.
Rukia could be a great character to pair with Ichigo. Since they have a strong bond in the original series, in the fanfiction, she could follow him into the other world or be summoned there later. Their combined power and friendship would make for an interesting dynamic as they face new challenges.
One popular character paired with Ichigo is Naruto. Their different power sets and personalities make for an interesting combination. Naruto's positive and determined attitude could contrast with Ichigo's sometimes brooding nature. Another is Luffy from 'One Piece'. Luffy's carefree and adventurous spirit next to Ichigo's more serious approach to protecting his friends can create some great stories.
Aizen Sousuke would be an interesting crossover character. Since he's so powerful and manipulative in the Bleach universe, seeing him in a different setting with Ichigo could create some really complex and intense storylines. They could be forced to work together against an even greater evil in a crossover universe.
One interesting character to crossover with Ichigo is Light Yagami from Death Note. The clash between Ichigo, who is a protector, and Light, who is a morally ambiguous character with the power to kill, would be very engaging. Saitama from One - Punch Man could also be a great choice. Saitama's overpowered nature and Ichigo's journey to become stronger would make for an interesting story. And what about Alucard from Hellsing? His vampire powers and Ichigo's powers related to the afterlife would create a really dark and exciting crossover.
Ichigo could meet Frodo Baggins. Frodo, being from a very different kind of world, would find Ichigo's situation strange. But they could bond over their shared sense of being out of place in some ways. Frodo could teach Ichigo about the importance of perseverance in the face of great odds, and Ichigo could protect Frodo from any potential threats in this crossover world with his swordsmanship.
Luffy from 'One Piece' would also be an interesting crossover character. Imagine Ichigo being abandoned on an island in the 'One Piece' world. Luffy's carefree yet determined nature could contrast with Ichigo's more brooding personality. They could embark on a journey together, with Ichigo learning about the concept of the 'One Piece' and using his powers in unexpected ways within this new world.
Maybe Naruto from Naruto could be a crossover character. His ninja skills and Ichigo's combat abilities could create some unique fight scenes. Also, their different ideologies about friendship and power could lead to some great character interactions.
Rukia could be one of the characters. Since she has a deep connection with Ichigo already in the original series, it would be easy to develop a more romantic aspect in the harem setting. Orihime is also a likely candidate, as she has strong feelings for Ichigo. And from other animes, a character like Saber from 'Fate/stay night' could be interesting. Her noble and powerful nature would contrast with Ichigo's more rough - around - the - edges personality.
One possible ally could be a powerful mage from a different anime in the crossover. This mage could help Ichigo understand the strange magic or energy in the new world he is stuck in. Also, Uryu might be an ally. His Quincy abilities could complement Ichigo's powers in Mugetsu form as they face new threats together.
In the world of Harry Potter, a crossover with Harry could be interesting. Ichigo's immortality would put him in a unique position in the wizarding world. He could bring his combat skills to Hogwarts and perhaps even help in the fight against Voldemort, while also learning about magic and how it differs from his own powers.